Casting moulds with corner plate coolant flow passages



CASTING MOULDS WITH CORNER PLATE COOLANT FLOW PASSAGES Filed July 5.1967 July 14,1970 G. HOYLE ET A1.

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CASTING MOULDS WITH CORNER PLATE COOLANT FLOW PASSAGES Filed July 5,1967 2 Sheets- Sheet 2 /N VEN TOPS Geoff-REY vHome EowARa mer/v @rmsATTORNEYS United States Patent Olce Patented July 14, 1970 3,520,353CASTING MOULDS WITH CORNER PLATE COOLANT FLOW PASSAGES Geoffrey Hoyleand Edward Martin Barrs, Sheiield, England, assignors to The BritishIron and Steel Research Association Filed July 5, 1967, Ser. No. 651,227Claims priority, application Great Britain, July 6, 1966, 30,274/ 66Int. Cl. B22d 27/ 04 U.S. Cl. 164-348 8 Claims ABSTRACT OF THEDISCLOSURE The disclosure concerns a mould for casting metal, thecorners of the mould being obtuse angled and coolant flow means beingprovided on the exterior faces of the mould sides and corners.

This invention is concerned with improvements in and relating to mouldsfor casting and more particularly to casting moulds for use inconjunction with electroslag refining equipment.

According to one aspect of this invention there is provided a mould forcasting metal comprising a plurality of side walls interconnected bycorner plates to provide obtuse angle corners in the cast product andmeans for delivering a ow of coolant down the exterior faces of the sidewalls and a flow of coolant along the outer faces of the corner panels.

In order that the present invention may be well understood there willnow be described two embodiments, given by way of example only,reference being had to the accompanying drawings in which:

FIG. 1 is a part sectional plan view on the line B-B of FIG. 2;

FIG. 2 is a part sectional elevation on the line A--A of FIG. l;

FIG. 3 is a transverse cross section of the walls of another embodimentof mould, and

FIG. 4 is a fragmentary elevation of one major wall of the mould of FIG.3.

The mould, which is of conductive material, is here open ended and thecavity is defined by four walls 1 interconnected by corner plates 2 sothat the transverse section of the mould and hence the cast product hasobtuse angle corners for example 135. The mould unit at the lower end issurrounded by a trough 3 and at the upper end by a header 4 which hasinwardly directed outlet apertures 5 to direct coolant, generally water,on to the exterior of the walls 1. The corner plates each in part definea coolant feed passage to pass coolant to the header from one of a pairof coolant inlet branches 6 coupled to an inlet pipe 7. An outlet 8 iscoupled to the trough. In a modication of the mould shown in FIGS'. 1and 2, the walls diverge in the downward direction of the mould so thatthe corner plates are trapezoidal.

In operation the mould is positioned on a suitable base and a slagpowder is fed into the mould. An electrode of metal to be refined is feddown into the slag, and a conductive path is established through theelectrode, slag and .the base or a second electrode. This causes slag tomelt and then the electrode to melt. The molten metal passes downthrough the slag and forms a pool in the mould above the base.

As the metal is removed from the electrode the slag is progessivelydisplaced upwards fby the metal accumulating in the mould, though a slagskin does form against the surface of the mould due to the chillingaction of the mould wall. Freezing takes place progressively and at anytime there is a comparatively small molten metal pool. On completion,the electrode is withdrawn and freezing continues until complete. Themould is then withdrawn from the casting.

Referring to FIGS. 3 and 4 there is shown a simplified embodiment ofmould in which the coolant feed passages are replaced by a pair ofspaced tins 9', each projecting outward from the junction of a wall 1'and a corner plate 2. A header 4 is provided surrounding the upper partof the mould with apertures as before for directing a spray on to thewalls 1 and additional apertures for directing a spray on to the cornerpanels. The additional apertures are arranged, as by being of largerdiameter, to give an increased flow of coolant at the corner panels andthe apertures nearest the ns are angled not only to direct the coolanttoward the corner panel face but also toward the adjacent iin to directcoolant into the angle defined by the fin and corner panel. The arrows10 of FIG. 4 diagrammatically show the directions of the coolant lflowfrom the header at a corner panel.

The above described moulds provide these advantages:

(l) Because the mould has a taper, and because the four wide-face panelsare rectangular, the four corner panels are trapezoidal. These cornerpanels would be diicult to cool =by direct spraying, especially if alarge mould taper was employed, due to the fact that the falling curtainof water would not be wide enough at its base to cover the full width ofthe corner panels.

(2) It would be difficult to cool square tapering ingots having orradiused corners by spray cooling. Corner cooling is facilitated bymaking the mould corners at and by ensuring a large flow of water inthis region. The method also ensures adequate cooling of the verticalcorner welds where increased wall thickness gives slower heat transfer.

(3) By cutting off the ingot mould corners and by virtue of the thickeringot slag skin produced at the corners due to the increased cooling, aningot free from a sharp corner is produced. This minimizes any tendencytowards segregation of elements in the casting at the columnar crystaljunction within the corners.

We claim:

1. relatively thin walled mould for casting metal comprising:

(a) a plurality of relatively wide side walls;

(b) relatively narrow corner plates interconnecting said side walls -toprovide obtuse angle corners in the cast product;

(c) means for delivering a ilow of coolant down the exterior faces ofsaid side walls and for delivering a fiow of coolant along the outerfaces of said comer plates, said means including a spray header;

(d) means for conveying coolant to said means (c);

and

(e) means defining corner plate coolant flow passages located at eachjunction of a side wall and a corner plate for restraining the coolantow over said corner plates from passing onto said side walls.

2. A mould according to claim 1 in which each corner plate istrapezoidal and of increasing Width in the direction of the end whichwill be lowermost and said side walls are rectangular.

3. A relatively thin walled mould for casting metal comprising (a) aplurality of relatively wide side walls;

(b) relatively narrow corner plates interconnecting said side walls toprovide obtuse angle corners in the cast product;

(c) spray header means having coolant discharge appertures fordelivering a flow of coolant down the exterior faces of said side walls;and

(d) means cooperating with said corner plates to dene coolant feedpassages for feeding coolant up said corner plates to said spray headermeans.

4. A mould according to claim 1, in which said restraining meanscomprises an outwardly projecting fin at each junction between a sidewall and a corner plate and in which said means for delivering a ow ofcoolant along the outer faces of said corner plates comprises portionsof said spray header associated with the corner plates, each saidportion having discharge apertures, at least some of which are directedtowards the corner plate and at least some of which are arranged todirect coolant into the angles formed between the corner plate and theassociated ns.

5. A mould according to claim 3 in which said spray header means is aspray header extending about the uppermost part of said mould with whichheader each passage is connected.

6. A mould according to claim 4 in which said spray header extends aboutthe uppermost part of the mould and has further portions associated withthe side walls, said further portions having additional coolantdischarge apertures for delivering the flow of coolant down the exteriorfaces of the side walls, at least some of the discharge apertures in thecorner plate portions being of a larger diameter than said additionalapertures.

7. A mould according to claim 1 in which said means for delivering a owof coolant delivers a greater flow along the outer faces of the cornerplates than down the exterior faces of the side walls.

8. A mould according to claim 2 in which said means for delivering a owof coolant delivers a greater flow along the outer faces of the cornerplates than down the exterior faces of the side walls.

References Cited UNITED STATES PATENTS 1,336,459 4/1920 Woodward164--128 2,829,410 4/1958 Beaver. 1,936,280 ll/l933 Williams 164-348 X2,479,191 8/1949 Williams et al. 249-79 3,448,790 6/1969 Maskall 249-79X 2,851,750 9/1958 Schaaber 249-78 X 1,781,392 11/1930 Hultgren 249-80FOREIGN PATENTS 276,210 8/ 1927 Great Britain. 764,015 12/1956 GreatBritain.

ROBERT D. BALDWIN, Primary Examiner

